Wire cloth tray

ABSTRACT

A wire cloth tray in which the interwoven longitudinal and transverse wires are gathered at each corner to form a rounded corner, the sidewalls and endwalls being bent over at their upper extents to define their top edges and each rounded corner being severed across its upper extent and the severed edges being welded throughout its length to connect all of the severed wires of each corner. The invention also relates to a reinforcing bar which extends parallel and adjacent to the sidewalls, extends through each corner, and has a short portion at each end lying parallel to the endwalls.

nited States Patent {72] Inventors Harold E. Pink; {56] References CitedRonald G. Daringer. Cambridge, Md. UNITED STATES PATENTS 5; Q J' 32 19692,904.21 1 9/1959 Bloomquist 220/19 1 l e g g 0i applicamn Ser No2,825.48] 4/1958 Glenny 220/19 705,163, Feb. 13. 1968, now abandoned.FOREIGN PATENTS 45 Patented Feb 2 7 617,600 2/1949 Great Britain 220/1973 ig Cambridge w Cloth p y 956,910 4/1964 Great Blltflll'l .2 220/19Cambridge, Md. Primary ExaminerGeorge E. Lowrance a corporal of MarylandAt10rney-Cushman, Darby & Cushman ABSTRACT: A wire cloth tray in whichthe interwoven longitudinal and transverse wires are gathered at eachcorner to [54] a g R form a rounded corner, the sidewalls and endwallsbeing bent alms rawmg over at their upper extents to define their topedges and each [52] US. Cl 220/19, rounded comer being severed acrossits upper extent and the 263/47 severed edges being welded throughoutits length to connect [51] Int. Cl B65d 7/20, all of the severed wiresof each comer. The invention also re- F27b 21/04 lates to a reinforcingbar which extends parallel and adjacent [50] Field of Search 220/ l 9.,83; to the sidewalls, extends through each corner, and has a short263/47, 48, 49 portion at each end lying parallel to the endwalls.

WIRE CLOTH TRAY This is a continuation of application Ser. No. 705.163filed Feb. l3, 1968. now abandoned.

BACKGROUND OF THE INVENTION This invention relates to a wire cloth trayand more particularly to a wire cloth tray for roller hearth heattreatment furnaces. Roller hearth furnaces might commonly employ rollsspaced 9-10 inches apart while the temperature in the furnace reachesbetween 2,050 F. and 2, l F.

The construction of the prior art is discussed hereinafter in greaterdetail in relation to FIG. 1 of the drawings. The corners of these priorart trays are formed by notching out the comers of a fiat piece of wirecloth, folding the sides up, and reinforcing and securing the corners kymeans of metal angles and wire clips. The sidewalls and end walls areknuckled over, but knuckling is expensive since each wire must be curledseparately. Moreover, knuckling limits to some degree the dimensionsavailable for trays since the bending must take place at a point givenwidth or length, the height of the sides is limited to the mesh count.

The comers of the prior art trays are held together by a metal angle andwire clip, and the cutting, bending and securing of the metal and wireclips at the corners is time consuming, expensive, and requires extrapieces of material. These corners present a basic problem when the trayis used in roller hearth furnaces. The comers are not continuous instrength at their bends. The wire clip is the only element holding thecorners together while the metal angle helps retain the 90 shape of thecomers. When the tray is under load and is subjected to the hightemperatures found in a roller hearth furnace, the combination of theload and heat tends to spread the comers of the tray apart, to allow theleading edge to sag, and to cause general tray deformation. Uponoccasion, the tray may tend to turn sideways in the furnace with theresult that the spread comers or, for that matter, the right-anglecomers are apt to hang up on the side of the furnace ifthey come incontact 'with it. This causes a furnace wreck" in which trays andproducts are piled up within the furnace, which naturally causesextensive damage and considerable down time.

SUMMARY OF THE INVENTION The invention relates to a woven wire clothtray in which the wire cloth is gathered at each comer to form a roundedcomer integrally connected to the end wall, the sidewall, and thebottom. The sidewalls and end walls are bent over at their upper extentsto define their top edges. Preferably, the end walls and sidewalls arefolded over inwardly to eliminate the cost of knuckling the individualwires. Each rounded corner is severed across its upper extent, and thesevered edges are welded throughout their length.

The present invention provides a cheaper, stronger construction whicheliminates the problems discussed above. The gathered rounded comersprovide a continuous comer structure for the tray. This continuousstructure helps support the width of the tray along the leading andtrailing edges of the tray. The rounded comers also reduce furnace wreckpossibilities. Not only is the tray stronger and more rigid, but theinherent flexibility of wire cloth for high-temperature use ismaintained.

The invention also contemplates using longitudinal reinforcing barswhich extend through the comers of the tray and extend for a shortdistance transversely of the tray and parallel to the end walls. Thesereinforcing members provide strength through the entire comer. The barsonly extend transversely for a short distance in order to reduce theweight across the forward and rear ends of the tray since such ends areoften unsupported and tend to sag under load and high temperatures.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary plan view ofthe prior art;

FIG. 2 is a fragmentary perspective view taken from above and looking atthe interior of a rounded gathered comer of the invention;

FIG. 3 is a fragmentary side elevational view of the tray;

FIG 4 is a fragmentary sectional view taken substantially along the line4-4 of FIG. 2;

FIG 5 is a fragmentary plan view of the tray showing the positioning ofreinforcing bars in the tray; and

FIG. 6 is a view taken substantially along the line 6-6 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 discloses a tray 10constructed according to the prior art in which the corners 12 arenotched out and the side and end walls (14 and 16) are then bentupwardly at approximately from the bottom 18. The side and end wallscome together at the comers, but the side and end walls are notintegrally joined at the corners. A metal angle 20 is used to retain the90 angle of each comer while a wire clip 22 holds the corners together.The free ends of the wire clip are in turn welded as at 24 to the metalangle 20. However, the corner tends to pull apart under load in ahigh-temperature furnace.

FIGS. 2-6 disclose the present invention. The tray 26 is constructedfrom a flat piece of woven wire cloth having interwoven longitudinalwires 28 and transverse wires 30. For example, the wire cloth may becomprised of 3 mesh of I05 inch diameter stainless steel wire.Initially, the piece of woven wire cloth is preferably rectangular orsquare. The corners are then preferably cut across on approximately a 45angle and the entire piece of cloth is placed on a die. That portion ofthe cloth which eventually forms the bottom 32 is forced down into thedie, not shown, thereby forming the sidewalls 34 and end walls 36 andthe gathered rounded comers 38.

The sidewalls 34, end walls 36 and gathered comers 38 are described forillustration purposes as being separate structural elements, but it willbe appreciated that the tray 26 is formed from a single piece of wirecloth. No cuts are formed into the interior of the cloth to accommodatethe formation of the corners, as in the prior art. The corners, wallsand bottom are all integrally connected.

The sidewalls 34 are folded upwardly from the bottom 32. The sidewallsare finished by bending over the upper portion 40 thereof to define theupper edge 41 of the sidewalls 34. The individual transverse wires couldbe knuckled over as illustrated in the plan view in FIG. 1. Thus,alternate transverse wires are bent inside and outside the sidewall.There are disadvantages and added costs to knuckling the sidewalls inthis manner, as described above. The preferred embodiment is disclosedin FIGS. 26 in which the upper portion 40 of the sidewalls are foldedover toward the interior of the ray and pressed against the inside ofthe sidewall. Thus, the uppermost longitudinal wire 42 in the sidewallshas every other transverse wire 30 crossing on top thereof. The foldedupper portion 40 of the sidewalls normally includes at least onelongitudinal wire 44 alternately engaged on opposite sides by thetransverse wires 30 defining the sidewalls.

The end walls 36 are constructed in a similar manner. The end walls arefolded upwardly from the bottom. The end walls are finished by bendingover the upper portion 46 thereof to define the upper edge 48 of the endwalls. The individual longitudinal wires could be knuckled over asillustrated in the plan view in FIG. 1. Thus, alternate longitudinalwires are bent inside and outside the end wall. For the reasons outlinedabove, the preferred embodiment, disclosed in FIGS. 26, has the upperportion 46 of the end walls folded over toward the interior of the trayand pressed against the inside of the end wall. Thus, the uppermosttransverse wire 50 in the end walls has every other longitudinal wirecrossing on top thereof. The folded upper portion 46 of the end wallsnormally includes at least one transverse wire 52 alternately engaged onopposite sides by the longitudinal wires defining the end walls.

The bent portions 40 and 46 of the sidewalls and end walls,respectively, give additional length and width support to the tray whileincluding the inherent flexibility of woven wire cloth forhigh-temperature use. Bending avoids the use of welds across the topedges of the side and end walls of the tray.

Welds would transform the basket into a rigid structure m which it mightbe expected that the welds would fail during high-temperature usebecause of different expansion and contraction properties of the weldmaterial and wire cloth. This is in contrast with the limited-area useof welds in the corners where welding is desirable for the reasonshereinafter set forth.

It is also contemplated that additional reinforcing stiffeners, notshown, could be inserted between the side and end walls and thecorresponding folded portions. This would make the upper edges of theside and end walls wider with the result that extra stiffness isprovided along these edges.

Each comer is provided with a gathered rounded corner 38. That is, thelongitudinal and transverse wires, 28 and 30, are gathered and drawnupwardly to form a rounded, continuous corner. The gathered corner isobviously integrally connected to the side and end walls and the bottom.Instead of the upper portion of the rounded comers being folded orknuckled over, the rounded corners are severed across the upper extentsthereof. As illustrated, each comer is severed so that it is ofapproximately the same height as the adjacent side and end walls. Thesevered edges 54 of each rounded corner are welded throughout the lengthof the rounded comer so as to connect all of the severed wires of eachcomer. Welding not only provides some strength to the comer, but it alsoprevents the ends from fraying or unraveling, and it serves as afinishing device. The welding material 56 used in the rounded comerspreferably engages the uppermost longitudinal wire 42 of the sidewallsand the uppermost transverse wire 50 of the end walls, as at 58 and 60respectively. If the upper portions of the gathered comers were knuckledor folded over, the individual wires of the comers might come unraveled.Moreover, such knuckling or folding would produce bulk of material inthe comers thereby preventing reinforcing bars from fitting in closelyto the corners, as described hereinafter.

When the tray is used in high-temperature operations, it tends to deformunder the load therein and even under the weight of the tray itself. Asa means of reducing deformation, reinforcing bars may be used. In theprior art, as shown in FIG. 1, such reinforcing bars 62 extend along thewall of the tray and terminate short of the comers. As illustrated inFIG. 5, the preferred embodiment of the tray includes a longitudinalreinforcing bar 64 extending the length of the sidewall 34 of the tray.The reinforcing bar is turned through or bent around the comer with thefree ends 66 of the longitudinal reinforcing bar extending transverselyof the tray and approximately parallel to the end walls 36. It will benoted that while this reinforcing bar is referred to as a longitudinalreinforcing bar, it includes transverse components 68 after it turnsthrough each corner. The turn through each corner is important in thatthe transverse components 68 keep the bar upright by preventing twistingso as to obtain the maximum bending strength of the bar. As shown inFIG. 6, the bar is rectangular in cross section and its narrow edge 70rests on the bottom 32 of the tray. Reinforcement through a completeturn of the comer is also provided by this construction. The bar is notwelded to the tray so that so that the tray and bar can expand andcontract separately. Inasmuch as the wire cloth material is lighter thanthe reinforcing bar, it heats up more rapidly than the reinforcing bar.Provision is also made for a transverse reinforcing bar 72, whichpreferably fits approximately between the free ends 66 of thelongitudinal reinforcing bar. As illustrated, the transverse reinforcingbar fits adjacent to the end wall and below the folded portion thereof.

The direction of movement of the tray is shown by the arrows 74 in FIGS.3-5. If the forward end of the tray were subjected to considerableweight, it would sag across its transverse width as ti came across oneof the rollers in a roller hearth furnace. If the sag became too great,the tray could catch on the next roller. Therefore, it is desirable tominimize the weight at the leading and trailing edges of the tray.According, the reinforcing bar 72 preferably has a smallercrosssectional area than the longitudinal reinforcing bar and isaccordingly lighter in weight.

L-shaped clips 76 are used to fasten the reinforcing bars to respectivewalls. The clips 76 are positioned against the reinforcing bars to holdthe same against the wall of the tray. The shorter leg 78 of the clipspass over the narrow top edge of the reinforcing bars and pass throughthe wall of wire cloth tray to be preferably welded on the outsidesurface of the wall, as at 80. The welds are then preferably groundflush. The longer leg 82 of the clips pass through the bottom of thetray and are preferably welded on the outside surface of the bottom, asat 84. The welds are then preferably ground flush.

It is anticipated that the concepts embodied in the rectangular traydescribed herein'could be employed for other different general shapeswhich could incorporate continuous comers. The trays can naturally beemployed for uses other than high-temperature uses. In such cases, therewould be little need for the reinforcing bars.

The trays described and claimed herein are defined as being made fromwire cloth having interwoven longitudinal and transverse wires. Thelongitudinal wires are defined as extending perpendicular to the endwalls and the transverse wires are defined as extending perpendicular tothe sidewalls. It will be appreciated that such terms are used fordescriptive purposes only and that the sidewalls could be shorter inlength than the end walls. In such a case, the longitudinal" wires wouldbe shorter than the transverse wires.

While a preferred from of the invention has been illustrated in thedrawings and discussed above, it should be adequately clear thatconsiderable modification may be made thereto without departing from theprinciples of the invention.

We claim:

1. A tray formed of woven wire cloth having interwoven longitudinalwires and transverse wires comprising:

a woven wire cloth bottom;

upwardly extending woven wire cloth sidewalls integrally connected tothe bottom;

upwardly extending woven wire cloth end walls integrally connected tothe bottom, one of the end walls defining the leading edge of the tray;

a gathered woven wire cloth rounded comer integrally connecting theforward end wall to the respective sidewalls at each forward comer, thegathered woven wire cloth rounded comer being integrally connected tothe bottom; and

the sidewalls and end wallsbeing bent over at the upper extent of eachto define the top edges of the sidewalls and end walls, and each roundedcomer being severed across the upper extent thereof to define the topedge thereof, the top edge of each rounded comer being welded throughoutits length to connect all of the respective severed wires of each comer.

2. The tray defined in claim 1 additionally comprising a gathered wovenwire cloth rounded comer at each rear corner integrally connecting therear end wall to the respective sidewalls and being integrally connectedto the bottom, each rear gathered comer being severed across the upperextent thereof to define the top edge thereof, the top edge of each rearrounded comer being welded throughout its length to connect all of therespective severed wires of each corner.

3. The tray defined in claim 2 whereinthe end walls and sidewalls arefolded over inwardly.

4. The tray defined in claim 2 wherein the individual longitudinal wiresand transverse wires of the end and sidewalls respectively are knuckledover.

5. The tray defined in claim 2 wherein the uppermost transverse wire inthe end walls and the uppermost longitudinal wire in the sidewalls areengaged by the weld material defining the top edges of the roundedcomers.

6. The tray defined in claim 5 wherein all of the longitudinal wires inthe end walls and transverse wire in the sidewalls are bent inwardly andwherein every other longitudinal wire in the end walls passes over theuppermost transverse wire of the respective end walls and wherein everyother transverse wire in the sidewalls passes over the uppermostlongitudinal wire of the respective sidewalls.

7. The tray defined in claim 2 additionally comprising a pair oflongitudinal reinforcing bars, the reinforcing bars being mounted withinthe tray and secured to the walls thereof, and each longitudinalreinforcing bar extending the length of the respective sidewalls andbeing turned through each corner with the free end portions of eachreinforcing bar extending transversely and approximately parallel to therespective end walls, and the free end portions of opposed reinforcingbars being transversely disposed from each other,

8. The tray defined in claim 7 wherein the longitudinal rein forcingbars have a rectangular cross section and wherein the narrow edge ofeach bar is seated on the bottom of the tray.

9. The tray defined in claim 8 wherein the reinforcing bars are held inplace by a plurality of inverted L-shaped members, the free end of thelong leg of each L-shaped member being secured to the bottom and theshort leg extending across the upper narrow edge of the reinforcing barand being secured to a wall of the tray.

10. The tray defined in claim 7 additionally comprising a pair oftransverse reinforcing bars mounted within the tray and secured to therespective end walls thereof, the transverse reinforcing bars extendingbetween the transversely extending, opposed free ends of thelongitudinal reinforcing bars.

11. The tray defined in claim 10 wherein the transverse reinforcing barsare of smaller cross-sectional area than the cross-sectional area of thelongitudinal reinforcing bars.

12. The tray defined in claim 10 wherein the transverse reinforcing barslie adjacent the end walls and underneath the bent over portion of theend walls.

13. A tray formed of woven wire cloth having interwoven longitudinalwires and transverse wires comprising:

a woven wire cloth bottom;

upwardly extending woven wire cloth sidewalls integrally connected tothe bottom;

upwardly extending woven wire cloth end walls integrally connected tothe bottom, the end walls being operatively joined to the bottom, theend walls being operatively joined to the respective sidewalls at eachcorner of the tray;

a pair of longitudinal reinforcing bars mounted against and contiguouswith the sidewalls of the tray, each longitudinal reinforcing barextending the length of the respective sidewalls and being turnedthrough each comer with the free end portions thereof extendingtransversely and approximately parallel to the respective end walls, andthe free end portions of opposed reinforcing bars being transverselydisposed from each other; and

means secured to the tray for holding the reinforcing bar against thesidewalls of the tray, the holding means adapted to permit relativemovement between the bar and the sidewall, such relative movementarising from different rates of expansion and contractions in heattreatment operations.

14. The tray defined in claim 13 wherein the longitudinal reinforcingbars have a rectangular cross section and wherein the narrow edge ofeach bar is seated on the bottom of the tra 1 5. The tray defined inclaim 14 wherein the reinforcing bars are held in place by a pluralityof inverted Lshapcd mcm bers, the free end of the long leg of eachL-shaped member being secured to the bottom and the short leg extendingacross the upper narrow edge of the reinforcing bar and being secured toa wall of the tray.

16. The tray defined in claim 13 additionally comprising a pair oftransverse reinforcing bars mounted within the tray and secured to therespective end walls thereof, the transverse reinforcing bars extendingbetween the transversely extending, opposed free ends of thelongitudinal reinforcing bars.

17. The tray defined in claim 16 wherein the transverse reinforcing barsare of smaller cross-sectional area than the cross-sectional area of thelongitudinal reinforcing bars.

18, The tray defined in claim 13 additionally comprising gathered wovenwire cloth rounded corner integrally connected to the bottom andintegrally connecting each end wall to the adjacent sidewalls 19. Thetray defined in claim 18 wherein the sidewalls and end walls are bentover at the upper extent of each to define the top edges of thesidewalls and end walls, and wherein each rounded corner is severedacross the upper extent thereof to define the top edge thereof, the topedge of each rounded corner being welded throughout its length toconnect all of the respective severed wires of each corner.

20. The tray defined in claim 19 wherein the end walls and sidewalls arefolded over inwardly.

21. The tray defined in claim 13 wherein the reinforcing bars aremounted on the inside of the sidewalls of the tray.

22. A tray formed of woven wire cloth having interwoven longitudinalwires and transverse wires comprising:

a woven wire cloth bottom;

upwardly extending woven wire cloth sidewalls integrally connected tothe bottom;

upwardly extending woven wire cloth end walls integrally connected tothe bottom, one of the end walls defining the leading edge of the tray;

a gathered woven wire cloth rounded corner integrally connecting theforward end wall to the respective sidewalls at each forward comer, thegathered woven wire cloth rounded comer being integrally connected tothe bottom; and

each rounded comer being severed across the upper extent thereof todefine the top edge thereof, the top edge of each rounded corner beingwelded throughout its length to connect all of the respective severedwires of each comer.

23. The tray defined in claim 22 additionally comprising a gatheredwoven wire cloth rounded comer at each rear corner integrally connectingthe rear end wall to the respective sidewalls and being integrallyconnected to the bottom, each rear gathered corner being severed acrossthe upper extent thereof to define the top edge thereof, the top edge ofeach rear rounded corner being welded throughout its length to connectall of the respective severed wires of each corner.

24. The tray defined in claim 22 wherein the sidewalls and end walls arebent over at the upper extent of each to define the top edges of thesidewalls and end walls.

Disclaimer 3,559,836.Harold E. Pink and. Ronald G. Daringer, CLOTH TRAY.Patent dated Feb. 2, 1971.

Cambridge, 181d. WIRE Disclaimer filed Feb. 10,

1972, by the assignee, C'ambridge Wire Cloth Company. Hereby enters thisdisclaimer to claims 22 and 23 of said patent.

[Oflim'al Gazette June 2'), 1972.]

1. A tray formed of woven wire cloth having interwoven longitudinalwires and transverse wires comprising: a woven wire cloth bottom;upwardly extending woven wire cloth sidewalls Integrally connected tothe bottom; upwardly extending woven wire cloth end walls integrallyconnected to the bottom, one of the end walls defining the leading edgeof the tray; a gathered woven wire cloth rounded corner integrallyconnecting the forward end wall to the respective sidewalls at eachforward corner, the gathered woven wire cloth rounded corner beingintegrally connected to the bottom; and the sidewalls and end wallsbeing bent over at the upper extent of each to define the top edges ofthe sidewalls and end walls, and each rounded corner being severedacross the upper extent thereof to define the top edge thereof, the topedge of each rounded corner being welded throughout its length toconnect all of the respective severed wires of each corner.
 2. The traydefined in claim 1 additionally comprising a gathered woven wire clothrounded corner at each rear corner integrally connecting the rear endwall to the respective sidewalls and being integrally connected to thebottom, each rear gathered corner being severed across the upper extentthereof to define the top edge thereof, the top edge of each rearrounded corner being welded throughout its length to connect all of therespective severed wires of each corner.
 3. The tray defined in claim 2wherein the end walls and sidewalls are folded over inwardly.
 4. Thetray defined in claim 2 wherein the individual longitudinal wires andtransverse wires of the end and sidewalls respectively are knuckledover.
 5. The tray defined in claim 2 wherein the uppermost transversewire in the end walls and the uppermost longitudinal wire in thesidewalls are engaged by the weld material defining the top edges of therounded corners.
 6. The tray defined in claim 5 wherein all of thelongitudinal wires in the end walls and transverse wire in the sidewallsare bent inwardly and wherein every other longitudinal wire in the endwalls passes over the uppermost transverse wire of the respective endwalls and wherein every other transverse wire in the sidewalls passesover the uppermost longitudinal wire of the respective sidewalls.
 7. Thetray defined in claim 2 additionally comprising a pair of longitudinalreinforcing bars, the reinforcing bars being mounted within the tray andsecured to the walls thereof, and each longitudinal reinforcing barextending the length of the respective sidewalls and being turnedthrough each corner with the free end portions of each reinforcing barextending transversely and approximately parallel to the respective endwalls, and the free end portions of opposed reinforcing bars beingtransversely disposed from each other.
 8. The tray defined in claim 7wherein the longitudinal reinforcing bars have a rectangular crosssection and wherein the narrow edge of each bar is seated on the bottomof the tray.
 9. The tray defined in claim 8 wherein the reinforcing barsare held in place by a plurality of inverted L-shaped members, the freeend of the long leg of each L-shaped member being secured to the bottomand the short leg extending across the upper narrow edge of thereinforcing bar and being secured to a wall of the tray.
 10. The traydefined in claim 7 additionally comprising a pair of transversereinforcing bars mounted within the tray and secured to the respectiveend walls thereof, the transverse reinforcing bars extending between thetransversely extending, opposed free ends of the longitudinalreinforcing bars.
 11. The tray defined in claim 10 wherein thetransverse reinforcing bars are of smaller cross-sectional area than thecross-sectional area of the longitudinal reinforcing bars.
 12. The traydefined in claim 10 wherein the transverse reinforcing bars lie adjacentthe end walls and underneath the bent over portion of the end walls. 13.A tray formed of woven wire cloth having interwoven longitudinal wiresand transverse wires comprising: a woven wire cloth bottom; upwardlyextending woven wire cloth sidewalls integrally connecteD to the bottom;upwardly extending woven wire cloth end walls integrally connected tothe bottom, the end walls being operatively joined to the bottom, theend walls being operatively joined to the respective sidewalls at eachcorner of the tray; a pair of longitudinal reinforcing bars mountedagainst and contiguous with the sidewalls of the tray, each longitudinalreinforcing bar extending the length of the respective sidewalls andbeing turned through each corner with the free end portions thereofextending transversely and approximately parallel to the respective endwalls, and the free end portions of opposed reinforcing bars beingtransversely disposed from each other; and means secured to the tray forholding the reinforcing bar against the sidewalls of the tray, theholding means adapted to permit relative movement between the bar andthe sidewall, such relative movement arising from different rates ofexpansion and contractions in heat treatment operations.
 14. The traydefined in claim 13 wherein the longitudinal reinforcing bars have arectangular cross section and wherein the narrow edge of each bar isseated on the bottom of the tray.
 15. The tray defined in claim 14wherein the reinforcing bars are held in place by a plurality ofinverted L-shaped members, the free end of the long leg of each L-shapedmember being secured to the bottom and the short leg extending acrossthe upper narrow edge of the reinforcing bar and being secured to a wallof the tray.
 16. The tray defined in claim 13 additionally comprising apair of transverse reinforcing bars mounted within the tray and securedto the respective end walls thereof, the transverse reinforcing barsextending between the transversely extending, opposed free ends of thelongitudinal reinforcing bars.
 17. The tray defined in claim 16 whereinthe transverse reinforcing bars are of smaller cross-sectional area thanthe cross-sectional area of the longitudinal reinforcing bars.
 18. Thetray defined in claim 13 additionally comprising gathered woven wirecloth rounded corner integrally connected to the bottom and integrallyconnecting each end wall to the adjacent sidewalls.
 19. The tray definedin claim 18 wherein the sidewalls and end walls are bent over at theupper extent of each to define the top edges of the sidewalls and endwalls, and wherein each rounded corner is severed across the upperextent thereof to define the top edge thereof, the top edge of eachrounded corner being welded throughout its length to connect all of therespective severed wires of each corner.
 20. The tray defined in claim19 wherein the end walls and sidewalls are folded over inwardly.
 21. Thetray defined in claim 13 wherein the reinforcing bars are mounted on theinside of the sidewalls of the tray.
 22. A tray formed of woven wirecloth having interwoven longitudinal wires and transverse wirescomprising: a woven wire cloth bottom; upwardly extending woven wirecloth sidewalls integrally connected to the bottom; upwardly extendingwoven wire cloth end walls integrally connected to the bottom, one ofthe end walls defining the leading edge of the tray; a gathered wovenwire cloth rounded corner integrally connecting the forward end wall tothe respective sidewalls at each forward corner, the gathered woven wirecloth rounded corner being integrally connected to the bottom; and eachrounded corner being severed across the upper extent thereof to definethe top edge thereof, the top edge of each rounded corner being weldedthroughout its length to connect all of the respective severed wires ofeach corner.
 23. The tray defined in claim 22 additionally comprising agathered woven wire cloth rounded corner at each rear corner integrallyconnecting the rear end wall to the respective sidewalls and beingintegrally connected to the bottom, each rear gathered corner beingsevered across the upper extent thereof to define the top edge thereof,the top edge of each reaR rounded corner being welded throughout itslength to connect all of the respective severed wires of each corner.24. The tray defined in claim 22 wherein the sidewalls and end walls arebent over at the upper extent of each to define the top edges of thesidewalls and end walls.